Patents by Inventor Tsunetoshi Saito

Tsunetoshi Saito has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11333828
    Abstract: An optical connection component includes: a plurality of types of optical fibers; a plurality of high relative refractive-index difference optical fibers in each of which a relative refractive-index difference between a core and a cladding is larger than a relative refractive-index difference in each of the plurality of types of optical fibers and which are fusion spliced to the plurality of types of optical fibers; and a fixing member having a plurality of V-shaped grooves that receive the high relative refractive-index difference optical fibers with coating removed, the fixing member being configured to fix relative positions of the high relative refractive-index difference optical fibers and an optical element when optically coupling the high relative refractive-index difference optical fibers, which have been fusion spliced to the plurality of types of optical fibers, to the optical element. The high relative refractive-index difference optical fibers are of the same type.
    Type: Grant
    Filed: September 15, 2020
    Date of Patent: May 17, 2022
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masanori Takahashi, Mitsuhiro Iwaya, Tsunetoshi Saito
  • Publication number: 20200408991
    Abstract: An optical connection component includes: a plurality of types of optical fibers; a plurality of high relative refractive-index difference optical fibers in each of which a relative refractive-index difference between a core and a cladding is larger than a relative refractive-index difference in each of the plurality of types of optical fibers and which are fusion spliced to the plurality of types of optical fibers; and a fixing member having a plurality of V-shaped grooves that receive the high relative refractive-index difference optical fibers with coating removed, the fixing member being configured to fix relative positions of the high relative refractive-index difference optical fibers and an optical element when optically coupling the high relative refractive-index difference optical fibers, which have been fusion spliced to the plurality of types of optical fibers, to the optical element. The high relative refractive-index difference optical fibers are of the same type.
    Type: Application
    Filed: September 15, 2020
    Publication date: December 31, 2020
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masanori TAKAHASHI, Mitsuhiro IWAYA, Tsunetoshi SAITO
  • Publication number: 20190219766
    Abstract: A tapered waveguide is optically connected to an end surface of an optical fiber bundle part, and has a tapered part that changes in outside diameter in a tapered shape. The fiber bundle part is optically connected to the end surface of the large-diameter side of the waveguide. The entire waveguide has a substantially uniform index of refraction. A delivery fiber is optically connected to the end surface on the small-diameter side of the waveguide. As with the fiber bundle part the delivery fiber passes through a hole in a capillary and is affixed. The capillaries are each affixed to a retaining member such that the fiber bundle part, the waveguide, and the delivery fiber are disposed on the same axis and optically connected. The waveguide is retained in a state floating from the retaining member, and the outside surface of the waveguide is not in contact with the retaining member.
    Type: Application
    Filed: March 22, 2019
    Publication date: July 18, 2019
    Inventors: Kengo Watanabe, Kazunori Mukasa, Tsunetoshi Saito, Yoshiki Nomura
  • Patent number: 10139574
    Abstract: A plurality of holes are formed in a ferrule. The holes are at sites penetrated by the tips of optical fibers. An opening is formed in the upper surface of the ferrule and an internal housing section is exposed from the opening. The housing section is at a site at which an optical fiber holding member is housed. The optical fibers are held by the optical fiber holding member. The optical fibers are multi-core fibers. In other words, the optical fibers have a specified axis of symmetry in a cross-section vertical to the longitudinal direction of the optical fibers and have orientation relative to a rotation direction having the longitudinal direction as the axis thereof.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: November 27, 2018
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kengo Watanabe, Tsunetoshi Saito, Katsuki Suematsu, Mitsuhiro Iwaya, Kohei Kawasaki, Masahito Morimoto
  • Patent number: 10012803
    Abstract: This optical fiber connection structure connects a multicore fiber and a bundle structure bundling a plurality of optical fibers. The multicore fiber has a plurality of cores arranged in a lattice. The bundle structure includes closely packed optical fibers of the same diameter. The bundle structure is configured such that signal light optical fiber groups including signal light optical fibers and a dummy fiber group including dummy optical fibers are stacked in multiple layers. The signal light optical fiber groups are configured with the signal light optical fibers aligned in the mutually contacting direction. The signal light optical fiber groups and the dummy fiber group are stacked orthogonal to the alignment direction of the optical fibers constituting the respective fiber groups.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: July 3, 2018
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kengo Watanabe, Tsunetoshi Saito
  • Patent number: 9829652
    Abstract: In the present invention, a connector structure comprises a multi-core fiber and a ferrule. The multi-core fiber comprises a plurality of cores and a cladding that surrounds the cores. The ferrule holds the multi-core fiber. A tip of the multi-core fiber protrudes from an end face of the ferrule. A relation ??14.8/a is satisfied. In the formula, ? (?m) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber. The reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center. And a (?m) is a radius of the reference circle.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: November 28, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kengo Watanabe, Tsunetoshi Saito
  • Publication number: 20170235061
    Abstract: This optical fiber connection structure connects a multicore fiber and a bundle structure bundling a plurality of optical fibers. The multicore fiber has a plurality of cores arranged in a lattice. The bundle structure includes closely packed optical fibers of the same diameter. The bundle structure is configured such that signal light optical fiber groups including signal light optical fibers and a dummy fiber group including dummy optical fibers are stacked in multiple layers. The signal light optical fiber groups are configured with the signal light optical fibers aligned in the mutually contacting direction. The signal light optical fiber groups and the dummy fiber group are stacked orthogonal to the alignment direction of the optical fibers constituting the respective fiber groups.
    Type: Application
    Filed: August 4, 2015
    Publication date: August 17, 2017
    Inventors: Kengo WATANABE, Tsunetoshi SAITO
  • Patent number: 9692201
    Abstract: A bundle structure is obtained by arranging optical fibers having equal diameters in a close-packed arrangement around the outer circumference of a center optical fiber. The optical fibers are signal light optical fibers that transmit signal lights. The optical fiber is a pump light optical fiber that transmits pump light. The number of optical fibers is equal to the number of cores in the multi-core fiber. The bundle structure and the multi-core fiber are connected to one another by adhering or fusing. The cores and the cores are optically connected, and the core and the cladding are optically connected. When connecting, the mode field diameter of the cores and the cores are substantially equivalent. In addition, the outer diameter (diameter of circumscribed circle including optical fibers) of the bundle structure is set so as not to be greater than the outer diameter of the multi-core fiber.
    Type: Grant
    Filed: August 25, 2015
    Date of Patent: June 27, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kengo Watanabe, Tsunetoshi Saito, Yukihiro Tsuchida, Koichi Maeda, Katsunori Imamura
  • Publication number: 20170168247
    Abstract: A plurality of holes are formed in a ferrule. The holes are at sites penetrated by the tips of optical fibers. An opening is formed in the upper surface of the ferrule and an internal housing section is exposed from the opening. The housing section is at a site at which an optical fiber holding member is housed. The optical fibers are held by the optical fiber holding member. The optical fibers are multi-core fibers. In other words, the optical fibers have a specified axis of symmetry in a cross-section vertical to the longitudinal direction of the optical fibers and have orientation relative to a rotation direction having the longitudinal direction as the axis thereof.
    Type: Application
    Filed: February 27, 2017
    Publication date: June 15, 2017
    Inventors: Kengo WATANABE, Tsunetoshi SAITO, Katsuki SUEMATSU, Mitsuhiro IWAYA, Kohei KAWASAKI, Masahito MORIMOTO
  • Patent number: 9658410
    Abstract: An optical connector is structured so as to include a fiber connection structure therein. A multi-core fiber is included inside a ferrule, and affixed to the ferrule substrate. One end surface of the multi-core fiber is exposed to an end surface of the ferrule. The other end of the multi-core fiber passes through and is affixed to a capillary. A plurality of optical fiber pass through a capillary that faces the capillary, and are affixed thereto the capillary in the same manner. Seven optical fiber cores of the same diameter are joined in a close-packed arrangement in the fiber connection structure.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: May 23, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tsunetoshi Saito, Kengo Watanabe
  • Patent number: 9541707
    Abstract: A multicore fiber 1 includes a plurality of cores 3 disposed at predetermined intervals and surrounded by a cladding 5. The multicore fiber 1 also includes a marker 7 formed apart from the cores 3. The refractive index of the marker 7 is different from those of the cores 3 and the cladding 5. For example, the marker 7 may be made of a material having lower refractive index than that of the cladding 5. In this case, for example, the cores 3 may be made of germanium-doped quartz. The cladding 5 may be made of pure quartz. The marker 7 may be made of fluorine-doped quartz. Further, the marker 7 may be an empty hole.
    Type: Grant
    Filed: August 31, 2014
    Date of Patent: January 10, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tsunetoshi Saito, Katsunori Imamura, Kengo Watanabe
  • Publication number: 20160347645
    Abstract: A production method of an optical fiber preform includes: preparing a plurality of bar-shaped first preforms and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and an assembly step of: matching the through holes of the second preforms to make communication holes; and inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other. In at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other.
    Type: Application
    Filed: August 9, 2016
    Publication date: December 1, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tomohiro GONDA, Ryo MIYABE, Katsunori IMAMURA, Tsunetoshi SAITO, Ryuichi SUGIZAKI
  • Publication number: 20160231511
    Abstract: In the present invention, a connector structure comprises a multi-core fiber and a ferrule. The multi-core fiber comprises a plurality of cores and a cladding that surrounds the cores. The ferrule holds the multi-core fiber. A tip of the multi-core fiber protrudes from an end face of the ferrule. A relation ??14.8/a is satisfied. In the formula, ?(?m) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber. The reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center. And a(?m) is a radius of the reference circle.
    Type: Application
    Filed: April 20, 2016
    Publication date: August 11, 2016
    Inventors: Kengo WATANABE, Tsunetoshi SAITO
  • Publication number: 20160028206
    Abstract: A bundle structure is obtained by arranging optical fibers having equal diameters in a close-packed arrangement around the outer circumference of a center optical fiber. The optical fibers are signal light optical fibers that transmit signal lights. The optical fiber is a pump light optical fiber that transmits pump light. The number of optical fibers is equal to the number of cores in the multi-core fiber. The bundle structure and the multi-core fiber are connected to one another by adhering or fusing. The cores and the cores are optically connected, and the core and the cladding are optically connected. When connecting, the mode field diameter of the cores and the cores are substantially equivalent. In addition, the outer diameter (diameter of circumscribed circle including optical fibers) of the bundle structure is set so as not to be greater than the outer diameter of the multi-core fiber.
    Type: Application
    Filed: August 25, 2015
    Publication date: January 28, 2016
    Inventors: Kengo WATANABE, Tsunetoshi SAITO, Yukihiro TSUCHIDA, Koichi MAEDA, Katsunori IMAMURA
  • Publication number: 20160020573
    Abstract: An optical-fiber-bundle structure is connected to one end of a multi-core fiber. The multi-core fiber has a tapered section formed therein. The outside diameter of the multi-core fiber and the core pitch thereof decrease in the tapered section. It is possible for the multi-core fiber to have an increasing core pitch on the connection-side thereof which connects to the optical-fiber-bundle structure; hence, it is possible to use an easy-to-use large-diameter optical fiber as the optical fiber to be provided in the optical-fiber-bundle structure. When connecting another multi-core fiber to the other end of the multi-core fiber, it is possible to match the outer diameters thereof; hence, when fusion splicing to one another, it is unlikely for a positional shift of the cores to occur.
    Type: Application
    Filed: August 25, 2015
    Publication date: January 21, 2016
    Inventors: Kengo WATANABE, Tsunetoshi SAITO, Yukihiro TSUCHIDA, Koichi MAEDA, Katsunori IMAMURA
  • Patent number: 9225141
    Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: December 29, 2015
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro Tsuchida, Koichi Maeda, Yu Mimura, Hiroshi Matsuura, Kengo Watanabe, Tsunetoshi Saito, Ryo Miyabe, Shigeto Matsumoto, Keiichi Aiso, Ryuichi Sugizaki
  • Patent number: 9158064
    Abstract: A multicore fiber has a plurality of cores formed at predetermined distances and surrounded by a cladding. A bundle structure includes optical fibers joined in a close-packed arrangement. Specifically, one optical fiber is arranged at a center, and six optical fibers are arranged around the optical fiber arranged at the center. Accordingly, cores of the optical fibers are arranged at equal distances. The optical fibers are bonded together with an adhesive. Accordingly, claddings of adjacent optical fibers are in contact with each other either directly or via the adhesive. The adhesive also fills spaces between the optical fibers.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: October 13, 2015
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tsunetoshi Saito, Kengo Watanabe
  • Publication number: 20150055923
    Abstract: A multicore fiber 1 includes a plurality of cores 3 disposed at predetermined intervals and surrounded by a cladding 5. The multicore fiber 1 also includes a marker 7 formed apart from the cores 3. The refractive index of the marker 7 is different from those of the cores 3 and the cladding 5. For example, the marker 7 may be made of a material having lower refractive index than that of the cladding 5. In this case, for example, the cores 3 may be made of germanium-doped quartz. The cladding 5 may be made of pure quartz. The marker 7 may be made of fluorine-doped quartz. Further, the marker 7 may be an empty hole.
    Type: Application
    Filed: August 31, 2014
    Publication date: February 26, 2015
    Inventors: Tsunetoshi SAITO, Katsunori IMAMURA, Kengo WATANABE
  • Patent number: 8920042
    Abstract: An optical connector includes a fiber holder with guide holes for guiding optical fibers, a space communicating with the guide holes and to accommodate the optical fibers, and a deformable member that forms at least a part of the fiber holder and causes the space to deform or displace to allow a part or all of the optical fibers to bend in the space.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: December 30, 2014
    Assignees: Fujitsu Limited, Furukawa Electric Co., Ltd.
    Inventors: Tsuyoshi Aoki, Shigenori Aoki, Hidenobu Muranaka, Mitsuhiro Iwaya, Tsunetoshi Saito, Katsuki Suematsu
  • Publication number: 20140240819
    Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.
    Type: Application
    Filed: April 4, 2014
    Publication date: August 28, 2014
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro TSUCHIDA, Koichi Maeda, Yu Mimura, Hiroshi Matsuura, Kengo Watanabe, Tsunetoshi Saito, Ryo Miyabe, Shigeto Matsumoto, Keiichi Aiso, Ryuichi Sugizaki